Here is a 1977 PU-0 that has a "1" code so may have been a new model at the time. It measures 7.81k.

Correct me if i'm wrong but Greco had 3 catalogs in 77 Vol 6, 7, and 8. Pu-0 is first mentioned in vol 8 which would likely be the ass end of 77 so those pu-0s of Wulfs are aug 1977 which would fit in with being a prototype?

And the pickups of mine, Serial 15.12= Dec 12 1975 so we could say the guitar is likely to be from very early 1976 and the pickups could well be a prototype of U-4000's which came out mid 1976.?

It is a bit odd to me that a prototype would have the "PU-0" already stamped in the back though, you would think that would happen with a production model only. Just saying, I don't know what it all means.

I do remember (to finish this sentence!) someone with early PU-2s that had PU-2 stamped on in ink rather than embossed. Can't find a picture though.

Last edited by wulfman on Wed Oct 05, 2011 5:45 am; edited 1 time in total

Yes that and I just found two different sets of pickups with the same serial, one set has u-3000 stamped the other set has nothing stamped and the serial number starts with 1 from 1976. u-3000 started earlier than that so I don't know what it all means either.

Hmm not much makes sense really. The only thing that has any merit is the supposed Email from maxon that they are production line numbers. There is no rhyme or reason to the first number. I guess it comes down to what ever had to be made on any particular day or week due to demand determined what production line they were made on, hence variying numbers on the same model pickups.
Nothing else fits.

As for number 1 being a prototype, maybe there is merit to that too but as with most things from this era there are exceptions.

Thank you for your enquiry. We made the pickups for Greco and Ibanez, etc. Please read the attached article from the UK magazine "GUITAR BUYER" for detailed information.

Maxon guitar pickup serial number consisted of five-digit number.
Period used: up to and including 1977
The serial number: ABCDD
A: production line code (1: prototype line (very rare pickup), the other numbers are the production line numbers.)
B: year of manufacture (e.g. 1977 was shown as "7".)
C: month, 1=Jan ... 9=Sep., 0(zero)=Oct., X=Nov., .(dot)=Dec.
DD: day of the month (01 to 31)
If A is 1 (prototype line), B is the year code and CDD are not disclosed.

Maxon guitar pickup serial number consisted of six-digit number.
Period used: After 1977.

The serial number: ABCCDD
A: production line code (1: prototype line (very rare pickup), the other numbers are the production line numbers.)
B: year of manufacture (e.g. 1977 was shown as "7".)
CC: month, 01=Jan ... 09=Sep., 10=Oct., 11=Nov., 12=Dec.
DD: day of the month (01 to 31)

If A is 1 (prototype line), B is the year code and CDD are not disclosed.

We tried to find the old technical information and checked thoroughly about all the pickups. However, there was no information that we can trace from model number such as U-4000. All the information we have in the warehouse is just delivery numbers for guitar assembly factory.

All the information we can provide is as follows.
Alnico3, Alnico 5 and Alnico8 were used for Alnico pickups. For Ceramic pickups, Ferritic2 and Ferritic3.2 were used.

Regarding the serial number, we sent you the information before. That's the all the information we can provide.